Infants are devoid of intestinal flora at birth. As a result of contact with the mother during birth and subsequent feeding with human milk or formula milk, the intestinal flora rapidly develops. During the development, the intestinal flora is still immature and its equilibrium is fragile. Human milk-fed infants are less afflicted by infections or diseases than formula-fed infants. Hence, human milk-fed babies have less gastro-intestinal infections in terms of both incidence and duration, less atopic diseases such as allergy, eczema, less colics and cramps, and less constipation than formula-fed infants. Also afflictions occurring later in life, such as childhood obesity, diabetes, and asthma are related to the type of feeding during the earliest stages of life, with the human milk-fed infants being in the advantage.
Generally, the intestinal flora of human milk-fed infants is primarily composed of Bifidobacteria and Lactobacilli. Human milk contains human milk oligosaccharides, which are a growth factor for Bifidobacteria in the intestine of infants. The flora of formula-fed infants is more diverse and contains in general more Bacteroides, Clostridium and Enterobacteriaceae species. Formula-fed infants have about one-tenth to roughly two-third the number of Bifidobacteria of human milk-fed infants. Bifidobacteria and Lactobacilli are considered to be important in maintaining a well-balanced intestinal microbiota and it has been postulated that Bifidobacteria and Lactobacilli have several health-promoting effects, including the prevention and/or treatment of diarrhoea and intestinal infections. Furthermore, Bifidobacteria and Lactobacilli have been shown to play a role in the immune system of the host.
The approach up to now was to promote Bifidobacteria in general, i.e. on the genus level. The genus Bifidobacterium consists of many different species, which differ in metabolism, enzyme activity, oligo- and polysaccharide utilisation, cell wall composition, and interaction with the host's immune system. Therefore, not every species of Bifidobacterium has the same functional effect on the infant. B. adolescentis is more prevalent in the flora of adults and allergic infants, and is less common in faeces of healthy infants. B. animalis/B. lactis is not naturally occurring in humans. In healthy infants the Bifidobacteria flora is mainly composed of B. infantis, B. breve and B. longum. It is the aim of the present invention to achieve a flora in formula-fed infants that is reminiscent to the flora of human milk-fed babies on a Bifidobacterium species level.
EP1105002 describes the use of two different non-digestible carbohydrates to improve the intestinal flora. The carboydrates may especially comprise galacto-oligosaccharides and fructo-polysaccharides.